This invention relates generally to closed body wound drainage devices and particularly, to methods and apparatus for clearing obstructions from closed wound drainage devices of the type having suction source connected to a closed container and a suction line connected to the suction source, for withdrawing fluid from a body wound.
Patient wounds, including surgery sites, often generate excess body fluids, which must be drained from the wound for proper patient healing. Wounds should be drained in a manner which minimizes the likelihood of contamination and infection. In order to prevent wound infection, sterile, closed wound drainage systems, that prevent environmental contact with the wound or the system, are often used by health-care practitioners.
Sterile, closed wound drainage systems generally have a suction source connected to a sealed container, which receives the drained body fluid and a suction line connected to the container. Known examples of suction sources in closed wound drainage systems include inflatable balloons or other types of bladders in generally rigid, sealed containers; compressible, biased bladders or vacuum lines. The suction line, or a device connected to the suction line, such as a suction catheter, is routed to the wound site for receipt of the drainage fluid. Many closed wound drainage devices have a one-way check valve between the container and the suction line, which allows drainage fluid flow from the suction line to the container but prevents flow from the container to the suction line. Examples of known, closed wound drainage systems include the devices shown in U.S Pat. Nos. 3,742,952; 3,752,158; 3,889,677 and 4,559,035. Closed wound drainage systems that are actually marketed included the DAVOL.RTM. brand models CWS 400 and RELIAVAC .TM., as well as the Snyder brand HEMOVAC.RTM. evacuators. Many known closed wound drainage systems are presterilized, disposable units.
In use, closed wound drainage systems tend to clog with obstructions created by the drainage fluid, thereby reducing system efficiency. In extremely clogged systems, the unit can no longer evacuate fluid from the patient's wound, leading to wound complications.
Past attempts to remove system obstructions by removing the suction line from the patient, opening the system and cleaning the system components were unsatisfactory, because opening the system violated system sterility and increased risks of patient infection complications. The other known alternative of discarding and replacing clogged drainage systems with new ones prevented infection but was expensive. Accordingly, there has been a long-felt need by health-care practitioners for a closed wound drainage system that can be cleared to remove obstructions without compromising system sterility.
Health-care practitioners often want to withdraw samples of wound drainage fluids for laboratory analysis. The only known way to obtain fluid samples from closed wound drainage systems is to open the sealed container and empty fluid from the container. Fluid emptied from the container is exposed to the atmosphere and may be contaminated by microorganisms that do not inhabit the system. Also, microorganisms may enter the container portion during the emptying procedure and subsequently grow therein, but they may not enter the suction line. Thus, laboratory analysis of fluid withdrawn from the container may not accurately indicate which microorganisms, if any inhabit the wound site or the drainage system suction line.
It is an object of the present invention to create a closed wound drainage system that is clearable to remove internal obstructions in the system without opening the system.
It is also an object of the present invention to create a closed wound drainage system from which wound fluids can be withdrawn without opening the system.